Twitter's 140 characters are so passe. The new hotness on the tech scene – for at least the next five minutes – is zero-character communication.

"Yo" is gloriously simple, and simply stupid. Like Chindōgu, the Japanese art of inventing perfectly useless gadgets that nonetheless look like they should solve a common problem, it hovers the fine line between a fantastic, "I wish I'd thought of that" idea, and one which should have been laughed out of the room before anyone even bothered to write it down.

The way it works is: You choose a username. You "add friends" by typing in their usernames. Then, when you want to message them, you hit their name. It sends a "Yo". If they hit your name, they send a Yo back.

That's it.

A received Yo just shows up as that friend's name rising to the top of the friend list, while a swipe right tells you how long it's been since they sent it. A swipe left lets you delete a Yo, or block a friend entirely, if they're sending … I don't know, malicious Yos? I can't work out how one could send a malicious Yo, but this is the internet, so someone will find a way.

Beyond that, there's a count of how many Yos you have received, and the ability to share your Yo name on other platforms including Twitter and Facebook, but this is already more thought than the app really deserves.